Enhancement of electrical stability of polyaniline films in aqueous media by surface modification with polypyrrole

Surface modification of freestanding polyaniline (PANi) films via coating with polypyrrole (PPY) was successfully carried out in an electrochemical cell with organic acid as dopant. The modified films have higher conductivity than the PANi films and the electrical stability in deionized water and moderately basic aqueous media is also significantly enhanced. Surface compositions of the pristine and modified films were determined using X-ray photoelectron spectroscopy (XPS). The effect of coating thickness on the stability enhancement and mechanical strength of the PANi films were investigated.